• Journal of Science Education
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• v.39 no.1
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• pp.1-14
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• 2015

This study aims to find out the effect of pre-service elementary teachers' experiences of inquiry performance in the life on their images about a scientist and science teaching anxiety. Thus, this study selected 162 college juniors who completed 'Science Teaching Material Research & Teaching Methods' for one semester at a university of education. Groups of 3 to 4 pre-service teachers were made to select one of the 10 experimental topics and inquired it for themselves, and make a presentation about the results before the other pre-service teachers. The results of this study can be summarized as below. Firstly, as a result of investigating pre-service elementary teachers' opinions about the characteristics of scientists, it was found that they thought of scientists prudent, intellectually superior, creative, and hard-working, but did not consider them artistic or religious, no matter if they had inquiry performance experiences. Especially, to such characteristics as intellectually-superior, creative, open-minded, outgoing and responsible, they showed more positive responses after inquiry performances. Besides, in scientists' activity types shown in pre-service elementary teachers' drawing pictures of a scientist, 'Experimental Activity' increased most after their inquiry performances, and in the place of activity, 'Laboratory' was most since it was related to activity types. Secondly, as a result of examining per-service elementary teachers' science teaching anxiety before and after inquiry performances, it was found that they showed statistically significant differences in all the domains, scientific knowledge, inquiry class preparation and inquiry class management. This finding could be interpreted as their inquiry experiences had positive effect on their having confidence in teaching science.

• Journal of Educational Research in Mathematics
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• v.19 no.1
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• pp.63-80
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• 2009

This paper has a purpose to find out the important points about linguistic factors suited to the assessment purpose and mathematics teaching/learning that a word-problem sentence has to possess. We also examine the degree of understanding of sentence and the perceptive/emotional reactions of students toward two different kinds of word-problem sentences that have same mathematical contents, but different linguistic structures. The objects of this thesis are 124 students from the third to sixth grade in an elementary school. We execute assessment of simple-sentence-word-problem and complex-sentence-word-problem that have same mathematical contexts, but different linguistic structures. Then we have compared and examined their own process of solving the two types word-problems and we make up questionnaire and have an interview with them. The conclusions are as followings: First, simple-sentence-word-problem is more successful to suggest an information for solving a problem than complex one. Second, it is hard to find the strategy for solving a problem in complex-sentence-word-problem than simple one. Third, students think that suggested information and mathematical knowledge are different according to the linguistic structure in the process of perceiving the information after reading a word-problem. Fourth, in spite of same sentence type, the negative mental reaction is showed greatly to complex-sentence-word-problem even before solving a problem.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.3
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• pp.179-186
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• 1989

According to the results from the experiments of selecting a suitable variety of forage rape and comparing productivity and nutrient quality between forage rape and oil seed rape, Velox appeared to be the most suitable variety in terms of productivity and nutrient quality at the southern area of Korea among the varieties used in the experiments. Consequently, Velox was grown under two different cultural methods, individual culture and population culture, and productivity and variation of nutrient quality during the growth period were observed and compared between the cultural methods. The results from the experiment are summarized as follows: 1. Although variations were great in plant fresh weight and plant dry matter weight among plants, individual culture showed significantly higher value in these characters at the 1 % level than population culture. Plant fresh weight and plant dry matter weight were largely dependent upon the amount of branches in case of individual culture. However, in population culture, they were equally dependent upon the amount of branches and main stem. There was no significant difference in dry matter percentage between cultural methods, and main stem showed highest dry matter percentage. 2. Content of crude protein was decreasing gradually as plants continued to grow. Individual culture showed higher content of crude protein than population culture from 90 to 120 days after sowing but vice versa from 180 days after sowing to flowering stage. Contents of fiber such as NDF, ADF, cellulose and lignin was low at the early stage of growth. It was increasing gradually as plants grew older and at the latter stage of growth plants under individual culture showed higher values in contents of fiber. 3. In vitro dry matter digestibility (IVDMD) of both stems and leaves was decreasing gradually as plants grew older. Plants under individual culture showed higher IVDMD of stems than plants under population culture, but no significant difference in IVDMD of leaves was observed between cultural methods.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.1-8
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• 2015

Ultra-wide-angle wireless endoscopes are demonstrated in this paper. The endoscope is composed of an ultra-wide-angle camera module and wireless transmission module. A lens unit with the ultra-wide FOV of 162 degrees is designed and manufactured. The lens, image sensor, and camera processor unit are packaged together in a $3{\times}3{\times}9-cm3$ case. The wireless transmission modules are implemented based on UWB- and WiFi-based platform, respectively. The UWB-based module can transmit HD video to a computer in resolution of $2048{\times}1536$ (QXGA) and the frame rate of 15 fps in MJPEG compression mode. The maximum data transfer rate reaches 41.2 Mbps. The FOV and the resolution of the endoscope is comparable to a medical-grade endoscope. The FOV and resolution is ~3X and 16X higher than that of a commercial high-performance WiFi endoscope, respectively. The WiFi-based module streams out video to a smart device with th maximum date transfer rate of 1.5 Mbps at the resolution of $640{\times}480$ (VGA) and the frame rate of 30 fps in MJPEG compression mode. The implemented components show the feasibility of cheap medical-grade wireless electronic endoscopes, which can be effectively used in u-healthcare, emergency treatment, home-healthcare, remote diagnosis, etc.

• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.36-44
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• 1984

Waters, sediments and crucian carps samples collected bimonthly from Nakdong river during- the period of August 1982 to June 1983 were analyzed for organophosphorus pesticide residues by GLC equipped with a flame photometric detector. Among the environmental samples, IBP, diazinon, phenthoate, parathion, malathion and fenitrothion residues were found only in waters and crucian carps and sediments samples were devoid of the residues. In addition, seasonal variations of the residues in waters and crucian carps were observed. Waters and crucian carps samples collected in August, when pesticides are generally in great demand, contained all the organophosphorus pesticide residues while no organophosphorus were detected in waters and crucian carps samples collected in February, April or December. The most abundant residues in the two environmental samples were diazinon and IBP and residue levels of parathion, malathion and fenitrothion were found extremely low.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.138-148
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• 2006

This study was carried out to evaluate the structural safety fur both the attached wind-protecting wall in greenhouse and the detached one installed outside. Regarding the attached wind-protecting wall in greenhouse, the analysis was conducted by doing a fluid-structure coupled field analysis using both CFX-5.7 and ANSYS 8.1 and also under the design condition of an instantaneous maximum wind velocity of $30.9m{\cdot}s^{-1}$. Three kinds of the width ranged from 30 to 90cm were considered in this study. With regard to the detached wind-protecting wall, the structural saffty was analyzed under the pressure difference of 1,117 Pa which corresponded to a wind velocity of $50m{\cdot}s^{-1}$ and the analytical results were also compared with theoretical ones. The result showed that there was little difference in the distribution of velocity overall and total pressure on the lateral side according to the width of the attached wind-protecting wall, but greenhouse with wind-protecting widths of 30 to 60cm has been reinforced to the extent of about 11% when compared with the case of being without the wall. The result also showed that the detached wind-protecting wall with a main-column interval of 3m was not stable so that it was necessary for the detached wind-protecting wall to be adequately reinforced to secure structural stability. Finally, there was great difference between analytical results and theoretical studies. The difference meant that there was some possibility of including errors when a theoretical study was done in three dimensional structure.

• Journal of Life Science
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• v.25 no.5
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• pp.507-514
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• 2015

D-Xylulose is phosphorylated to D-xylulose-5-phosphate by D-xylulose kinase before it enters glycolysis via the nonoxidative pentose phosphate pathway. A gene encoding a novel D-xylulose kinase (XK) from K. gwangalliensis strain SJ2 was sequenced and expressed in E. coli. The sequence of the isolated XK gene was 1,419 bp, encoding 472 amino acids. The XK protein was more closely related to the Arthrobacter phenanthrenivorans XK than to the Bifidobacterium catenulatum one, as reflected in the sequence identity (54.9% vs. 38.7%). The XK gene was subcloned into the pCold-II expression vector. The resulting plasmid was transformed into E. coli strain BL21 (DE3) cells and the expression of the recombinant XK protein was induced by the addition of IPTG. The resulting protein was expressed as a fusion protein of approximately 48 kDa containing a N-terminal six-histidine extension that was derived from the expression vector. The expressed protein was homogenized by affinity chromatography and showed enzymatic activity corresponding to D-xylulose kinase. XK enzyme kinetic studies with D-xylulose and ATP showed a Km of 250±20 μM and 1,300±50 μM, respectively. The results obtained from this study will provide a wider knowledge base for the characterization of D-xylulose kinase at the molecular level.

• Journal of Life Science
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• v.21 no.7
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• pp.923-931
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• 2011

In the present study, we investigated the effect of indole-3-carbinol (I3C), a natural compound present in vegetables, on the cell migration and invasion of OVCAR-3 ovarian cancer cells. Our results indicated that I3C inhibited the proliferation of OVCAR-3 cells, a process which was associated with inhibition of cell motility as determined by wound healing experiments and cell invasion studies. I3C treatment increased the tightness of the tight junctions (TJs), which was demonstrated by an increase in transepithelial electrical resistance and a decrease in paracellular permeability. The RT-PCR and immunoblotting results indicated that I3C repressed the levels of claudin-3 as well as claudin-4, proteins that comprise a major part of TJs and play a key role in the control and selectivity of paracellular transport. Furthermore, the activities of matrix metalloproteinase (MMP)-2 and MMP-9 were also decreased by treatment with I3C, which was connected with the down-regulation of their mRNAs and protein expression. The results suggest that I3C may be expected to inhibit cancer cell metastasis and invasion by restoring TJs and decreasing MMP activity in ovarian cancer cell line OVCAR-3.

• Journal of Life Science
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• v.27 no.10
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• pp.1225-1231
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• 2017

Disruptive expression patterns of the circadian clock genes are highly associated with many human diseases, including cancer. Cell cycle and proliferation is linked to a circadian rhythm; therefore, abnormal clock gene expression could result in tumorigenesis and malignant development. The molecular network of the circadian clock is based on transcriptional and translational feedback loops orchestrated by a variety of clock activators and clock repressors. The expression of 10~15% of the genome is controlled by the overall balance of circadian oscillation. Among the many clock genes, Period 1 (Per1) and Period 2 (Per2) are clock repressor genes that play an important role in the regulation of normal physiological rhythms. It has been reported that PER1 and PER2 are involved in the expression of cell cycle regulators including cyclins, cyclin-dependent kinases (CDKs), and CDK inhibitors. In addition, correlation of the down-regulation of PER1 and PER2 with development of many cancer types has been revealed. In this review, we focused on the molecular function of PER1 and PER2 in the circadian clock network and the transcriptional and translational targets of PER1 and PER2 involved in cell cycle and tumorigenesis. Moreover, we provide information suggesting that PER1 and PER2 could be promising therapeutic targets for cancer therapies and serve as potential prognostic markers for certain types of human cancers.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.493-498
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• 2003

Changes in amino acids content and antioxidative activity in the leaves of buchu (Allium tuberosum R.) at different harvesting times were investigated. Contents of protein, lipids and ash were the highest at the first harvest time, but decreased thereafter, whereas water content showed the reverse pattern. Amino acid contents were the highest at 2nd harvest time, major compositions being aspartic acid, alanine, and glutamic acid, which decreased thereafter. Antioxidative activities according to harvesting times also revealed the same pattern showing by the major nutrients. Correlation coefficients between antioxidative detecting methods in TEAC vs FRAP assay, FRAP vs DPPH assay, and TEAC vs DPPH showed 0.996, 0.992, and 0.987, respectively (p<0.001). The earliest-harvested buchu had the highest content of carotenoids, vitamin C, and total phenol, whereas the lowest of chlorophyll. Antioxidative effects of buchu, with vitamin C and total phenol contents have high coefficient correlations of 0.991 and 0.989, respectively.